I wasn't alive during this time, but I can guess that its safe to assume that although three point shooting was an option, it was probably a "last" option type of shot. Back in those days wasn't it about the big man's game?

You mean it was real basketball back then....yes

The 3pt line was added to the NBA at the start of the 79-80 season, it was a gimmick, brought in to capture the former ABA fans who were used to it.
The 3's were mainly used as an end of game strategy to try to catch up if behind....end of game meaning last seconds not last minutes.
Coaches didn't like it nor the lower shooting percentages, in fact it took a really long time before it became a legitimate option for teams.........we can thank ESPN for that......and it is the 3pt line that has killed the Center position in the NBA.

Think about how much the game would change if you took away the 3pt line.